重频Yb:YAG片状激光器电光调Q时空演化模拟计算和实验研究

Calculation and experimental research of the spatio-temporal dynamics of Q-switched rep-rated Yb:YAG disk laser

基于Yb3+抽运动力学,结合光线追迹的方法,建立了抽运过程中的放大自发辐射模型,得到激光介质中三维含时储能分布.将速率方程理论和角谱传播理论结合,对谐振腔内调Q脉冲的形成、传播过程进行建模计算,得到激光脉冲的时间-空间分布和光束质量因子变化规律.同时进行了激光二极管抽运重频Yb:YAG片状激光器电光调Q实验,并与模拟计算的结果进行了对比校核,印证了计算模型的正确性.这为主动调Q固体激光器的设计提供了参考.

Based on the energy-level structure of quasi-three-level Yb ion, an amplified spontaneous emission model in pumping process is set up. The stored energy density distribution and the energy that can be extracted in Yb：YAG crystal are calculated. Our calculation, which is based on the laser rate equations and the theory of anglular spectrum propagation, can simulate time- resolved evolution of the spatial intensity distribution and M2 factor of the laser pulses. At the same time, an experiment in laser diode-pumped Q-switched rep-rated Yb：YAG disk laser was performed. This model was proved to be correct by comparing the results of the experiment and calculation, which will be helpful in designing active Q-switched solid laser.